Joint device identification and data detection in physical layer for many devices in IoT

In this paper, we consider sparse index multiple access (SIMA) for uplink transmissions in a wireless system of a number of devices when a fraction of them are active. This multiple access scheme is suitable for the case that an access point (AP) needs to not only receive signals, but also identify active devices when there are a number of devices with unique identification sequences (the number of devices can be easily more than a million). We propose a two-stage transmission scheme and derive computationally efficient methods to estimate the channels of active devices in the first stage and to perform device identification within the physical layer together with data detection in the second stage using a well-known sparse signal estimation method in compressive sensing (CS).